Figure of the week: Climate change vulnerability and urban population growth

According to a study by the strategic consulting firm Maplecroft, the fastest growing cities in Africa are among the most susceptible to the threat of climate change over the next 30 years. Figure 1 combines the annual population growth of over 1800 cities from the U.N. World Urbanization Prospects database with a proprietary Climate Change Vulnerability Index (CCVI) to create a scatter plot showing the relationship between population growth and climate change.

The CCVI evaluates social, economic, and environmental factors to assess vulnerabilities across three core areas: exposure to climate-related natural disasters and sea-level rise; human sensitivity (in terms of population patterns, development, natural resources, agricultural dependency, and conflicts), and resilience (measuring the adaptive capacity of a country’s government and infrastructure) to combat climate change.

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Research Analyst - Global Economy and Development

Figure 1 shows a striking relationship between climate change risk and population growth. Looking at the size of the bubble, which represents the size of the city in 2018, it is noticeable that small and medium-sized cities face disproportionate climate change risk. According to the study, 79 of Africa’s cities are rated extreme risk by the CCVI, including 15 capital cities and major commercial hubs. This list includes Kampala, Dar es Salaam, Abuja, Lagos, Addis Ababa, and Luanda.

Figure 1: The relationship between population growth and climate change

The study also measured financial risk using International Monetary Fund growth projections to develop estimates of economic exposure to climate change in 2023. This measure assesses the proportion of a cities’ gross regional product that will be at risk of loss to climate change. Lagos, Nigeria, and Addis Ababa, Ethiopia, both had among the highest economic exposure valued at about $128.5 billion and $69 billion, respectively.